748
FXUS61 KCTP 181848
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
148 PM EST MON NOV 18 2024
SYNOPSIS
HIGH PRESSURE WILL BRING FAIR WEATHER TODAY AND TONIGHT. A WARM
FRONT WILL LIFT NORTHEAST ACROSS THE REGION WITH CLOUDS AND
SCATTERED SHOWERS INTO EARLY WEDNESDAY. A DEEP, ANOMALOUSLY
COLD CUT-OFF UPPER LOW WILL TRACK ACROSS FROM THE GREAT LAKES
INTO PENNSYLVANIA LATE THIS WEEK, PRECEDED BY AN OCCLUDED FRONT
PASSAGE WEDNESDAY NIGHT.
NEAR TERM /THROUGH TONIGHT/
DRIER AIR CONTINUES TO MOVE IN FROM THE NORTH BEHIND A COLD
FRONT THIS AFTERNOON WITH DEWPOINTS IN THE LOWER 40S AND
DROPPING ACROSS THE NORTHER TIER. AS DRIER AIR MOVES IN, THE
DECK OF STRATOCUMULUS ACROSS THE SOUTHWEST PART OF THE
COMMONWEALTH CONTINUES TO SLOWLY BUT SURELY ERODE THERE WHILE
MOSTLY SUNNY SKIES PERSIST FOR THE NORTHWEST, NORTHEAST, AND
SOUTHEAST QUADRANTS OF PA.
ANOTHER VERY MILD DAY IS UNDERWAY WITH HIGHS IN THE MIDDLE 50S
TO MIDDLE 60S (+10-15 DEGREES ABOVE THE HISTORICAL AVERAGE).
LOWER DEWPOINTS AND MOSTLY CLEAR SKIES WILL ALLOW FOR
TEMPERATURES OVERNIGHT TO FALL INTO THE 30S FOR MOST OF THE
AREA. THE COOLEST READINGS WILL BE ACROSS THE NORTHERN MOUNTAINS
WHERE A FEW SPOTS COULD GET TO FREEZING. PATCHY VALLEY FOG IS
POSSIBLE AS WELL.
SHORT TERM /TUESDAY THROUGH WEDNESDAY/
UPPER LEVEL RIDGING OVER THE AREA SHOULD PROVIDE CENTRAL PA
WITH MILD AND RAIN-FREE CONDITIONS FOR MOST OF TUESDAY. A
SLIGHTLY COOLER AIRMASS WILL SUPPORT HIGH TEMPERATURES ABOUT 5
TO 7 DEGREES LOWER ON TUESDAY COMPARED TO TODAY. WARM ADVECTION
ASSOCIATED WITH A WEAKENING SHORTWAVE LIFTING INTO THE GRT LKS
SHOULD LEAD TO INCREASING CLOUDS LATE TUESDAY/TUESDAY NIGHT WITH
THE CHANCE OF A FEW SHOWERS, MAINLY OVER THE W MTNS. SHOWERS
SHOULD DECREASE IN COVERAGE AND INTENSITY OVERNIGHT. RAINFALL
AMOUNTS COULD APPROACH A TENTH OF AN INCH ACROSS THE LAUREL
HIGHLANDS, WITH LESSER AMOUNTS FARTHER EAST.
FOCUS THEN SHIFTS TO A CUT-OFF UPPER LOW DROPPING INTO THE
MIDWEST. MODEL SOUNDINGS INDICATE AN EASTERLY FLOW OFF OF THE
ATLANTIC WILL LIKELY YIELD STRATUS OVER PARTS OF THE AREA WED,
ESPECIALLY OVER THE CENTRAL MTNS. FALLING HEIGHTS AND SURGING
PWATS ALONG A SOUTHERLY LOW LEVEL JET SHOULD THEN BRING
THICKENING CLOUDS AND AN INCREASING CHANCE OF SHOWERS ACROSS THE
ENTIRE AREA BY LATE WEDNESDAY OR WED EVENING. WE MAY NEED TO
EVENTUALLY UNDERCUT NBM MAX TEMPS WED, DUE ITS WARM BIAS IN
EASTERLY FLOW/CAD SCENARIOS.REGARDLESS, WEDNESDAY WILL BE THE
LAST MILD DAY FOR AWHILE A COOLER, MORE SEASONABLE AIR ARRIVES
BY THURSDAY.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
RECENT GUIDANCE ALL TRACKS A SURFACE COLD/OCCLUDED FRONT THROUGH
CENTRAL PA WED NIGHT IN ADVANCE OF AN UPPER LOW APPROACHING
FROM THE GRT LKS. STRONG LARGE SCALE FORCING AHEAD OF THE UPPER
LOW AND LOW LEVEL CONVERGENCE ALONG THE FRONT SUPPORTS A HIGH
CHANCE OF RAIN SHOWERS WED NIGHT. HOWEVER, PLENTY OF SPREAD
REMAINS WITH REGARD TO RAIN AMOUNTS. ENSEMBLE MEAN QPF IS IN THE
0.25 TO 0.60 INCH RANGE. HOWEVER, A DECENT NUMBER OF EPS
MEMBERS PRODUCE TOTALS >1 INCH ASSOCIATED WITH THE POTENTIAL OF
DEEPER GOMEX MOISTURE STREAMING NORTH AHEAD OF THE FRONT.
CURRENT GUIDANCE INDICATES A DRY SLOT WILL WORK INTO CENTRAL PA
THU MORNING, THEN A PERIOD OF CHILLY AND UNSETTLED WEATHER LOOKS
VERY LIKELY LATE THIS WEEK, AS THE UPPER LOW TRACKS ACROSS OR
JUST NORTH OF PA. A DEEP MOIST NORTHWEST FLOW ON THE WESTERN
PERIPHERY OF THE EXITING UPPER LOW SHOULD RESULT IN PERSISTENT
LAKE-ENHANCED, OROGRAPHIC PRECIPITATION FOCUSED OVER THE W MTNS
THURSDAY NIGHT INTO AT LEAST THE FIRST HALF OF NEXT WEEKEND.
MODEL THERMAL PROFILES CURRENTLY LOOK COLD ENOUGH TO SUPPORT THE
FIRST ACCUMULATING SNOW OF THE SEASON ACROSS THE HIGHER
ELEVATIONS OF THE ALLEGHENIES BETWEEN THU NIGHT AND SATURDAY,
BUT SNOWFLAKES COULD EXTEND SOUTHEAST OF THE ALLEGHENY FRONT AT
TIMES.
IN ADDITION TO FREQUENT PRECIPITATION AND BELOW NORMAL DAYTIME
TEMPERATURES, GUSTY WEST-NORTHWEST WINDS ARE ALSO ANTICIPATED
FRIDAY AND SATURDAY, AS A TIGHT GRADIENT DEVELOPS WEST OF AN
INTENSIFYING SURFACE LOW OVER EASTERN NEW ENGLAND. LATEST EPS
PLUMES INDICATE GUSTS OF 30-35MPH ARE LIKELY BOTH DAYS.
PERSISTENT CLOUD COVER AND COOLER TEMPERATURES ALOFT WILL KEEP
HIGH TEMPERATURES IN THE UPPER 30S TO NEAR 50F, WHICH WILL BE A
SIGNIFICANT CHANGE, BUT IS STILL ONLY A FEW DEGREES BELOW
NORMAL FOR THIS TIME OF YEAR.
AVIATION /19Z MONDAY THROUGH SATURDAY/
STRATOCUMULUS CONTINUE TO SLOWLY BUT SURELY ERODE ACROSS THE
LAUREL HIGHLANDS (JST/AOO) THIS AFTERNOON AS DRIER AIR WORKS IN.
MVFR CEILINGS WILL PERSIST AT JST THROUGH ABOUT 00Z BEFORE
SCATTERING OUT. LAST FEW OBS AT JST HAVE HAD IFR CEILINGS AND
VARIABLE MVFR/IFR REMARKS, BUT WILL PREVAIL MVFR AT THIS POINT.
ELSEWHERE, VFR WILL PERSIST OVERNIGHT AND INTO TUESDAY
AFTERNOON. PATCHY FOG IS POSSIBLE ACROSS THE NORTHWEST MOUNTAINS
AND LAURELS BY TUESDAY MORNING. NOT ENOUGH CONFIDENCE TO INCLUDE
FOG AT ANY TAF SITES AT THIS POINT (HIGHEST PROBABILITY AT
JST/BFD, POSSIBLE AT IPT, UNV, AND AOO).
CLOUDS WILL BEGIN TO INCREASE TOMORROW AHEAD OF A WARM FRONT
THAT WILL BRING LIGHT SHOWERS TO WESTERN AIRFIELDS TUESDAY
AFTERNOON. RESTRICTIONS SHOULD HOLD OFF UNTIL AFTER 21Z IN THE
WEST WITH IFR CONDITIONS DEVELOPING OVERNIGHT.
OUTLOOK...
TUE NIGHT...RESTRICTIONS LIKELY WEST
WED...RESTRICTIONS LIKELY, MAINLY NW. MORE WIDESPREAD
RESTRICTIONS WITH RAIN AND LLWS WED NIGHT.
THU-FRI...RESTRICTIONS LIKELY WITH RAIN AND SNOW SHOWERS, MAINLY
ACROSS THE MOUNTAINS. WINDY.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...LAMBERT/FITZGERALD
NEAR TERM...LAMBERT/BANGHOFF
SHORT TERM...LAMBERT/BANGHOFF
LONG TERM...FITZGERALD/BANGHOFF
AVIATION...BANGHOFF
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